1. Field of the Invention
The present invention concerns a lamination system for thermocompression bonding of a transparent film on a surface of an ID card on which such as a photograph of a person and personal data are printed. More specifically, the present invention concerns an improvement of the wasteless type lamination system for laminating the transparent film on the surface of the ID card, successively cutting a continuous transparent film that has been rolled in a supply roll into a predetermined length, in which a defect that occurs in a card straightening process is remedied.
2. Description of the Prior Art
Recently, ID cards of various type are being widely used. In order to protect an ID card from tampering or to improve the life of the ID card, a transparent film of about 30 microns in thickness is laminated by a thermocompression bonding on a surface of the ID card on which information data are printed. Lamination systems such as disclosed in U.S. Pat. Nos. 5,807,461 and 5,783,024 are known as systems suitable for such lamination.
In the lamination system disclosed in U.S. Pat. No. 5,807,461, a transparent film pre-cut in a predetermined shape (a patch) is mounted on a carrier (a base sheet). The carrier is provided with sensor marks (index markings) for detecting the position of the pre-cut patch on the carrier. The lamination system detects the sensor mark prior to the lamination to detect the position of the pre-cut patch, then tears the patch from the carrier and laminates the patch on the surface of the printed ID card by thermocompression bonding. Such lamination system is undesirable in view of the operation cost and the protection of environment, since the carrier is thrown away as waste material.
The above problem was solved in a lamination system disclosed in U.S. Pat. No. 5,783,024 and the system is being practically used. In this lamination system, a leading edge of a continuous transparent laminate film is drawn out from a supply roll, then transferred along a supply path, then cut in a predetermined length, then laid on a printed ID card transferred along another supply path at the convergence zone of the two supply paths, and then laminated on the surface of the ID card by thermocompression bonding using a heat roller provided at the downstream. This lamination system, called wasteless type lamination system, is advantageous since the laminate film is used after being cut in a necessary length, and accordingly, no waste carrier such as in the lamination system-disclosed in U.S. Pat. No. 5,807,461 is left.
In this thermocompression bonding process, the laminated ID card tends to be bent into a form concave toward the heat roller, since heat and pressure are applied to one side of the laminated ID card by the heat roller. Accordingly, a card straightening means, for straightening the bent laminated ID card, comprising rollers supported on an adjustment plate, is provided at the downstream of the heat roller in the lamination system.
In the lamination system such as disclosed in U.S. Pat. No. 5,783,024, lamination is practiced as follows. The continuous transparent laminate film is loaded in a form of a supply roll on a supply spindle. A leading edge of the continuous laminate film is drawn out from the supply roll and transferred along a film transfer path. The continuous laminate film of which the leading edge is drawn out is hung on a roller composing a first transfer means, then passed between two cutting blades of a cutter, then transferred thorough a second transfer means composed of rollers, and then passed under a film detection sensor.
On the other hand, the printed ID card is put into an inlet of the lamination system. Then the printed ID card is transferred along a card transfer path, and then transferred to a point of convergence, composed of a pair of rollers, at which the film transfer path and the card transfer path converge, after being positioned for registration using an detection signal detected by a card edge detection sensor.
After that, the cut laminate film is laid on the printed ID card, then the cut laminate film and the printed ID card are transferred into a place between the heat roller and a platen roller to be applied predetermined heat and pressure. As a result, a heat adhesive layer of the cut laminate film is activated and the cut laminate film is laminated on the printed ID card by thermocompression bonding. In general, the heat roller is made of an aluminum material and is treated to have a fluoro resin lining to avoid sticking of a material melted out of the printed ID card. The platen roller is made of a heat-resisting rubber material.
In the thermocompression bonding process as explained above, the laminated ID card tends to be bent into a form concave toward the heat roller, since the laminated ID card passes between the heat roller and the platen roller that differ with each other in temperature and in rigidity. Accordingly, the card straightening means for straightening the bent laminated ID card is provided at the downstream of the heat roller and the platen roller. The card straightening means comprises a pair of rollers supported by the adjustment plate. While the laminated ID card is being passed between these rollers, the transfer path of the ID card is tilted by tilting the adjustment plate, and the reverse bend to the concave bend is applied to the laminated ID card between the heat roller and the card straightening means, to straighten the bent ID card. Additionally, distance between the heat roller and the card straightening means is set so that they do not interfere with each other and that a sufficient bending moment to straighten the bent ID card is applied to the bent ID card.
In the card straightening process as explained above, the laminated ID card leaves the heat roller while being applied the bending moment to straighten the bent ID card. Accordingly, the trailing edge of the ID card is strongly pressed to the heat roller when leaving the heat roller, a portion of the ID card is melted and the melted material sticks to the surface of the heat roller, even though the roller is treated to have a fluoro resin lining. Accordingly, there is a problem that the stuck material sticks on the surface of the succeeding ID card to be laminated next.
Additionally, in case that the distance between the heat roller and the card straightening means is relatively long, there is a problem that straightening of the bent ID card is insufficient.
These problems degrade the quality of finished ID cards. Particularly, for a ID card with magnetic stripes on the back, if the straightening of the bent ID card is insufficient, reliability in xe2x80x9cread/writexe2x80x9d of magnetic data is degraded.
It is an object of the present invention to solve the above problems and to provide a lamination system capable of raising the quality of the laminated ID cards and capable of straightening the bent ID card in the lamination process.
To achieve the above object, a lamination system according to the present invention comprises a film transfer means for transferring along a first transfer path a continuous film with a heat adhesive layer on a surface and drawn out from a supply roll, a cutting means provided along the first transfer path for cutting the film in a predetermined length, a card transfer means for transferring an ID card along a second transfer path that converges with the first transfer path at a predetermined point of conversion, a thermocompression bonding means for laminating the film cut in the predetermined length and laid on a surface of the ID card transferred, to the ID card at the downstream of the point of conversion, a card straightening means provided at the downstream of the thermocompression bonding means for straightening the ID card laminated and bent during the thermocompression bonding, in which a spring up suppression means for suppressing a spring up of a trailing edge of the laminated ID card leaving the thermocompression bonding means is provided between the thermocompression bonding means and the card straightening means.
Further according to the present invention, the spring up suppression means comprises a rotary element freely rotative.
Alternatively, the spring up suppression means comprises a card guide member having a gap that enables the passage of the laminated ID card and the suppression of the spring up of the trailing edge of the laminated ID card.
In the lamination system according to the present invention, since the spring up suppression means for suppressing spring up of the trailing edge of the laminated ID card leaving the thermocompression bonding means is provided between the thermocompression bonding means and the card straightening means, the trailing edge of the laminated ID card is not pressed to the heat roller when the laminated ID card leaves the thermocompression bonding means. Accordingly, the trailing edge of the ID card is prevented from melting, no melted material sticks to the surface of the heat roller, and thus the surface of a successive ID card to be laminated next is prevented from being spoiled by a melted material. Further, since the straightening force for the bent ID card is maintained also in the process in which the heat applied by the heat roller is being cooled after the trailing edge of the ID card is released from the thermocompression bonding means, the straightening of the bent ID card after lamination is improved.